But according to psychologist Leslie Zebrowitz at Brandeis University, it’s not the shape of your eyes or the size of your nose that matters most. People will most likely judge you based on four rather unusual facial features, instead.

Zebrowitz’s research, which was recently published in the journal Current Direction in Psychological Science, examined how we form first impressions of other people. By analyzing how our brains react to certain faces, she boiled the most favorable facial characteristics down to four traits: babyfaceness, familiarity, fitness, and emotional resemblance.

Babyfaceness describes people with “baby faces,” or those who have large eyes, short chins, round faces, and large foreheads. According to Curiosity, “Seeing a more baby-like face could make us treat that person more kindly, given our evolutionary soft-spot for youngins.”

Likewise, the more familiar and “fit” (read: healthy) your face looks, the more people will judge you as someone who is “likable, intelligent, and capable.” And lastly, showing positive emotional expressions on your face is a good sign of what Zebrowitz calls “emotional resemblance.” While you can’t control all of these factors, you can improve your emotional resemblance by using this body language that builds trust naturally.

So the next time you meet someone new, forget about putting your best foot forward—and put your best face forward, instead. You’ll want to know the other unexpected ways people are judging you, too.